A common challenge for drugs approved by the FDA is the occasional lack of drug availability for patients in need thereof. Accordingly, a significant unmet need exists for the disclosed processes of preparing drugs in a continuous and controlled manner as opposed to the more traditional batch preparations. To achieve continuous manufacturing, PAT must be developed that accurately monitor properties of the pharmaceutical compositions without interrupting the continuity of the processes. PAT, however, are spectroscopic in nature and must be correlated to references to be of any use. This correlation to references requires running many samples in a timely fashion using HTT HPLC techniques disclosed herein. It is also envisioned that HTT HPLC can be used to test the concentration of API in the final composition as either a back-up to PAT or when PAT is not available.